32/36 DGEV Jetting l18

[mantas]

Here is the deal. No matter how i set up my idle screw i get backfires out the carb or out the tailpipe. Here are my carb specs below, can anyone see any flaws with this set up or does it seem fine?

 

Air Correctors: 165 / 7/0 (what the hell is 7/0)?

Pump: 50

Aux Venturi: 3.5 / 3.5

Jets: 130 / 140

Emulsion tubes: F50 / F50

Main Venturi: 27 / 26

 

Can anyone shed some light here? I will go ahead and check the Primary Venturi in the mean time and report back. Seems like everytime i step on the throttle lightly it will backfire, if i gun it the thing goes. This used to only happen in 3rd gear, now its in 2nd after messing with the idle screw.

[yello620]

I think that the 130 primary main might be a little to lean.

 

And what idle jets do you have?

 

What is your timing set at?

[ggzilla]

Here is the suggested tuning for a stock L18:

Main Venturi: 26/27

Aux Venturi: 3.5/3.5

Main Jet: 140/135

Em Tube: F50/F6

Air Corr Jet: 165/160

Idle Jet: 55/50

Pump Jet: 50

Needle Valve: 2.00

[Laecaon]

Mine is jetted with whatever came stock in the kit you order for the L16. It ran better on my L18 than it did on my L16. And now that I bored my motor out (gained 90cc) , it runs even better. The only real thing I would gripe about, is the transition from Idle to primaries when cold is terrible.

 

 

Do you have a points distributor?

[banzai510(hainz)]

I just bolt them on and they work.

 

adjust the mixture and timming is usually enough

[ggzilla]

Yes, backfires are caused by something else. The carb adjustment just makes it better or worse, but doesn't get at the root cause.

 

Instead of messing with the idle screw, set the idle speed and mixture correctly.

 

 

the transition from Idle to primaries when cold is terrible.

Yes, that's what a choke is for. Properly choked, any engine should run as good or better cold than when warm.

[mantas]

Here is the suggested tuning for a stock L18:

Main Venturi: 26/27

Aux Venturi: 3.5/3.5

Main Jet: 140/135

Em Tube: F50/F6

Air Corr Jet: 165/160

Idle Jet: 55/50

Pump Jet: 50

Needle Valve: 2.00

 

I got a few jets to mimic this set up. We will see what happens. Thanks, and i believe i found one of your other posts to come up with my shopping list.

 

I think that the 130 primary main might be a little to lean.

 

And what idle jets do you have?

 

What is your timing set at?

 

Yeah 130 i thought was on the lean side too, i got a 135 ordered and a few others to get this up to specs - i hope.

Idle jets are 45/50, and i think i need something more like 50/55 for this.

 

Timing is fine on the crank and the cam, the distributor however says im all the way on the advanced mark, even though the V on cam aligns with mark and the pulley is right at 0 i believe.

 

I just bolt them on and they work.

 

adjust the mixture and timming is usually enough

 

Timing looks spot on except the distributor is all the way on the advanced side. I think you posted a video of how to set the distributor but im a bit affraid to mess with the timing, could you let me know how to do that in "stupid" i don't think English will work for me when it comes to this subject hahaha.

[ggzilla]

His video is for installing the distributor.

 

You can adjust timing within the normal range by rotating the distributor. Too far advanced will make the engine not run well at high RPM.

[mantas]

His video is for installing the distributor.

 

You can adjust timing within the normal range by rotating the distributor. Too far advanced will make the engine not run well at high RPM.

 

I'll try and retard the timing a bit tonight, whats a good spot for an l18 with webers? 12BTDC? Thanks in advance. I feel like im bombarding all the wizards with questions but please forgive me, i need this car going asap so i can tear into the bmw to do a gasket.

[banzai510(hainz)]

7-14 might be good. But you says webers? is this twin Then I would go 12-14.

its close enough.

if you got twin them maybe they not sync correctly.

We are not mind readers what you have. You say you got a webers but in the 620 photo looks like you just got a down draft 32/36.

 

if your motor is timmed correctly which sounds like it is. V notch ect.. then the last to time is the electrical. Thts the dizzy. You just loosen the 10mm head and dial the dizzy to the timming light on the crank with 31 plug wire.

 

adjust the mixture and redo. run it up a hill and try again.

[ggzilla]

L18 with or without webers wants the same timing. If you have a long duration cam, you want less timing, but more advance which you can only get by recurving the distributor. So short of that, set it to stock timing. Better to be safe than sorry. Advanced timing can damage an engine.

[mantas]

7-14 might be good. But you says webers? is this twin Then I would go 12-14.

its close enough.

if you got twin them maybe they not sync correctly.

We are not mind readers what you have. You say you got a webers but in the 620 photo looks like you just got a down draft 32/36.

 

if your motor is timmed correctly which sounds like it is. V notch ect.. then the last to time is the electrical. Thts the dizzy. You just loosen the 10mm head and dial the dizzy to the timming light on the crank with 31 plug wire.

 

adjust the mixture and redo. run it up a hill and try again.

 

Yup its a 32/36 DGEV downdraft. And the vacum advance must be plugged up while im setting this? My neighbors won't be too happy - again.....

Going to try the timing situation tonight, only problem is i dont' know what the idle is at, since i don't have a tach.....i was waiting on a tach from some ebay shop and they screwed up the order. Can i just grab one from pep boys and it wil work off the bat (autometer or something like that).

[Laecaon]

If this is a points dizzy, I would replace the points and condensor if they are of unknown age. Especially if you are backfiring out the carb and exhaust, which to me says inconsistent timing.

[ggzilla]

Yes, sounds like inconsistent timing, but not the wrong timing. Points will do this especially if they are more than a year old.

 

You don't need to run the engine to set the timing. Turn it to the 10 degree mark before TDC (by hand, or with a wrench).

 

Then rotate the distributor until

* for points distributor, key on engine off, turn the distributor back, then forward until points open (when it sparks)

* for 1978-1979, the teeth inside the cap line up.

 

That's it. It will be close enough to run very well. No tach or timing light needed.

[mantas]

If this is a points dizzy, I would replace the points and condensor if they are of unknown age. Especially if you are backfiring out the carb and exhaust, which to me says inconsistent timing.

What is a points dizzy? I definitely don't know the age of it, but i'll try and get a tach, autozone has a dizzy for 77 plus 19 core, are those even worth a go?

[Laecaon]

Dont buy a new Dizzy from autozone.

 

Dont bother buying one for a 77. 78 or 79 would be preferred.

 

This is a points dizzy.

 

[ggzilla]

Just put a new set (points + condensor) in. Cost about $10, and only requires a feeler gauge to set the gap. Use the spec in your repair manual or the one on the underhood sticker.

[mantas]

Dont buy a new Dizzy from autozone.

 

Dont bother buying one for a 77. 78 or 79 would be preferred.

 

This is a points dizzy.

 

 

AHA! Yup i do have a points dizze then. Thanks for clearing it up, im a bit of a noob when it comes to carb related cars and older ignition systems. Quite honestly the only cars i've worked on have been nissans and all efi. Ive had to figure out this whole carburation system situation within the last month or so and i keep learning something new thanks to you guys on this forum.

Just put a new set (points + condensor) in. Cost about $10, and only requires a feeler gauge to set the gap. Use the spec in your repair manual or the one on the underhood sticker.

 

I'll stick to the manual for instructions, i always print a manual and keep a set in the garage anytime i get a new car and have that stuff as a pdf on almost every electronic device in the house. I think i'll have to tackle the Dizzy and timing situation tomorrow, its a bit of a drive to get the points + condensor (only autzone hub has them). I guess this is going to be a good learning experience and i'll be a bit more familiar with these L series engines and my least favorite part - timing. For now - off to install my rear KYB shocks.

[mantas]

Well, changed the jets and it fires right up. The idle screw was not even in the right place but the thing runs at 1k rpm and purrs like a kitten. In the mean time i did the pinto fr shocks and replaced rears, wires up rpm gauge, did led dash lights and ordered the disc brake conversion from beenani. Hopefully all i need to do is set timing and adjust the idle screw but i can tell you right away the jets were completely fucked up in this thing because it never fired up so easily before and ran on its on.

[mantas]

And tomorrow im getting some american racing rims 15x10 and taking it to a 15 year fender rolling and pulling vet to get the thing looking like its supposed to.

[mantas]

Here is the suggested tuning for a stock L18:

Main Venturi: 26/27

Aux Venturi: 3.5/3.5

Main Jet: 140/135

Em Tube: F50/F6

Air Corr Jet: 165/160

Idle Jet: 55/50

Pump Jet: 50

Needle Valve: 2.00

 

 

Im assuming all numbers on left are primary the right is secondary?

 

Also my dizzy has 2 sets of points and condensers realized it when i popped it open. And when i run the timing light im at like 5BTDC, but my dizzy is all the way advanced how do i reset this? Lift out the dizzy and reposition it?

[banzai510(hainz)]

there is a 8mm bolt underneath try loosen that and that might help moving there plate in the right direction so you get more movemnt in the timming plate.

 

if you need to figure out how to put in a dizzy correctly watch the whole vid

 

but watch below first

 

you should have seent his already

http://www.youtube.com/watch?v=_aBTjhJMByo

[ggzilla]

Left and right. No.

 

Primary is the smaller side . It could be on the left or the right

 

[mantas]

Banzai510 i watched the video again but before you posted, guess what? Im a dumbass and didnt pay much attention the first time around. My dizzy was at 1 o'clock. Pulled the pump drive out put at 11:28 and set the dizzy with the timing light at 12BTDC, i would say its completely dead on. Tuned the carb with new jets, and spent two hours driving that guy around town. Love the truck, idle drops a little if coming to a stop in neutral but i know the carb is a bit off still so that will get fixed tomorrow when my neighbors get a break from all the noise. I gotta say, should have listened the first time, all along it was timing and i kept looking for other problems like a damn idiot. The only good that came out of it, i got new shocks, rpm gauge and a rebuilt carb. Ggzilla you did quite a lot of helping too, so to both of you - hats off. Thanks again and ill be back for questions later. Time to crack a cold one and celebrate.

[banzai510(hainz)]

readjust the timming and mixture and speed screw and you should get it dialed in close to good